​How It Works

Radar was invented by the militaries of the world leading up to World War II as a method of detecting and determining direction and range to an enemy. The term RADAR was coined by the United States Navy: Radio Detection And Ranging. A scientist at M.I.T., working for the United States Air Force, came up with a way to use radar to detect weather. Interesting? Maybe not, but it is a good introduction to understanding how weather radar works

A radar signal travels at the speed of light: 186,280 statute miles per second. The radar tracks the time from transmission, reflection, and reception to determine the distance of the target.

(2) Direction: Radar Sweep Angle

Finding the target's direction

​The radar continuously sweeps from side-to-side, and only receives reflections from targets in the beam width during that instantaneous moment, enabling it to determine direction relative to the aircraft.

(3) Reflective Characteristics: Signal Amplitude

Determining reflection characteristics

The radar measures the amplitude of the reflected signal to determine the size of the return, displaying increasing amplitudes in green, yellow, and red (or more variations, depending on radar.)

How the Radar’s Information is Presented to the Pilot

Providing radar information to the display

​A "radial" of information isn't a "degree" of information, rather it is a series of colors for a snapshot in time for that particular direction. A wider beam width will paint all the weather in a particular distance to be the same. The narrower the beam width, the greater the fidelity of the information you are seeing.

How targets are displayed

The radial range bins appear side-by-side to make up a composite picture of the lateral view, a slice of the weather.